The largest US seizure of the pure and potent Asian variety of the stimulant, it was also the latest evidence of the global rise of powerful synthetic illegal drugs.

Two decades after the naturally derived drugs cocaine and heroin washed over global markets, this new peril is hitting shores from Asia to Europe like a tsunami. Synthetic drugs - principally amphetamines, methamphetamine, and the "party drug" Ecstasy - are already heavily used in some Northern "developed" countries but are now catching on among other youth populations.

The head of the UN's drug-control agency says the world is not ready for an "epidemic" that breaks familiar drug-trafficking patterns and is dependent on weak states in much the way international terrorism is.

"We are facing a structural change in the drug market," says Antonio Maria Costa, director of the Vienna-based UN Office for Drug Control and Crime Prevention, which is releasing a report about the synthetic boom this fall. "The old dynamic [with cocaine and heroin] that the South produces and the North consumes is collapsing," he adds, noting that the threat of a "lost generation" is now the worry of places like Manila and Kuala Lumpur as much as Albany and Amsterdam.

These synthetic drugs are made with cheap and easily available chemicals found in cough and allergy medicines. Billions of easily consumed mood pills are flooding youth markets globally, according to the UN report.

The US is not immune to the phenomenon. Methamphetamine and other synthetics are "spreading from the West Coast to the East Coast like a wildfire, and it's really pounding down in the Midwest," says Will Glaspy, a Drug Enforcement Administration special agent in Washington. "We consider this stuff to be the No. 1 threat in rural America today."